Harmful algal bloom

A harmful algal bloom (HAB) can refer to a dense aggregation of phytoplankton, algae or cyanobacteria in a marine or aquatic environment that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms or by other means. The term "red tide" is often used colloquially to describe these phenomena, however scientists now prefer the term HAB, since

1. not all algal blooms are harmful,
2. not all algal blooms cause discoloration of water, and
3. these blooms are not associated with tides.

Additional recommended knowledge

Weighing the right way

Essential Laboratory Skills Guide

Safe Weighing Range Ensures Accurate Results

HABs are often associated with large-scale marine mortality events and have been associated with various types of shellfish poisonings.

See also

• algal bloom
• red tide
• paralytic shellfish poisoning
• amnesic shellfish poisoning
• ciguatera fish poisoning
• diarrhetic shellfish poisoning